Basic cationic hair dyes have been available for use in cosmetic products for more than twenty years. They have been adapted for use in color refreshing shampoo and conditioners, temporary hair color gels, and cremes. The products are intended to enhance and refresh previously colored hair, neutralize an unwanted shade, bring new highlights, and create visible color change.
One of the main drawbacks for cationic dyes in many types of hair care products is they are not useful in combination with or within products containing anionic ingredients, particularly anionic surfactants. The combination of cationic dyes and anionic ingredient(s) in a single product, e.g., a color depositing shampoo, causes a reduction of foaming properties (in a shampoo, foaming is recognized as being a desirable attribute. A shampoo that does not foam or does not foam adequately or with a suitable foam quality generally has perceived consumer negatives) and reduced color deposition. The combination of the two could also cause precipitation of an unwanted anionic/cationic complex. Common industry practice therefore utilizes high levels/quantities of cationic dyes in order to compensate for these drawbacks while still achieving a desired level of color deposition. Consequently, existing color depositing shampoos must use greater amounts of dye in the products to account for the “waste” causing higher costs of goods and thus higher retail prices effectively rendering combined cationic dye with anionic surfactant products highly difficult to market.
The current industry alternative for color depositing shampoos is a combination of a cationic dye with amphoteric and/or nonionic surfactants. Those products do not suffer from the above stated disadvantages arising primarily from the opposing ionic charges of the dye and surfactant. Here again, however, there are well known disadvantages. One problem with coloring shampoos which are generally free of anionic surfactants (that is, they are based on nonionic, amphoteric and/or cationic surfactants) is that they have a tendency not to foam adequately or may have poor sensory properties associated with the foaming, such as a tendency for any foam that does generate to generate slowly, spread slowly, or to dissipate quickly. The viscosity of the product(s) is also difficult to control. Addition of a small amount of an anionic surfactant (which adds to the production steps and increases cost of goods) is sometimes done to improve the foaming properties of a dye product made with a nonionic, amphoteric and/or cationic surfactants, knowing the resulting product will suffer from decreased dye deposition and/or suffer long term stability issues such as tonal shifts, precipitation or separation.
Thus there is a need for a color depositing shampoo made with cationic dyes that is substantially free from anionic surfactants with good foaming properties to efficiently and effectively deliver the dyes to the hair. It would be highly beneficial to have a color depositing shampoo that can achieve equal, if not more, dye deposition (and thus color change) compared to existing products, using less dye within the compositions of those existing products. There is a need for a color depositing shampoo that has less waste of dye when used. There is a need for a lower cost to manufacture color depositing shampoo that can effectively deposit color with good foaming properties.
It is thus an object of the present invention to provide a shampoo based formulation that will efficiently color the hair and effectively clean the hair. It is also an object of the invention to provide a shampoo based formulation that will replace ordinary shampoo but also be useful as a hair dye, a composition with improved and more desirable foaming properties.
In addition, basic, cationic dyes are organic dyes that can undergo both oxidative and reductive processes. The reaction that leads to a reduction of a dye molecule by a substrate usually involves an electron or hydrogen atom transfer from the reducing agent to the dye. Free radicals are produced in solution and can undergo subsequent redox reactions with the dye molecule, creating a “bleaching” or degradation of the dye molecule. The bleaching or degradation of the dye molecule renders it inactive, creates problems with efficacy and limits the shelf life of a finished hair color product. The free radicals produced in solution are also a result of the oxidative degradation of fragrance oils or other components in the product. Exposure to UV light can also produce free radicals.
Fragrances are present in numerous end-use products, not only fine perfumes but also as additives in a large range of applications. Personal care products including shampoos are typically fragranced to increase consumer acceptability by masking malodors of base ingredients. Fragrance compositions typically contain between 10 and 100 natural and synthetic fragrance molecules encompassing several organic functional groups including alcohols, phenols, aldehydes and ketones, esters and lactone, terpenes, ethers, oximes, ketals, etc. However, some fragrances, in particular terpenes and aldehydes, are very sensitive to oxidation by molecular oxygen. The consequences are not only a loss of sensorial properties, but also the appearance of off-notes and/or undesirable coloring. The oxidation may also develop possible irritation, allergy and sensitivity and free radicals may react with other components within a formula. Fragrance formulators strive to inhibit oxidation by adding antioxidants, such as BHT or other phenolics.
To prevent fragrance molecules from oxidative degradation, different types of antioxidants are commonly used. They can be classified into basically two classes according to the mechanism of action: (1) the primary or chain-breaking antioxidants and (2) the secondary or preventative antioxidants that do not react with the radicals but act as chelators, deactivate singlet oxygen, absorb ultraviolet radiation, or scavenge oxygen itself.
It is common practice in the cosmetic industry to determine (test) the shelf-life and stability of a formulation by placing the product samples at different environmental conditions for a set period of time. The conditions vary in temperature and light levels and are meant to simulate what will happen to the product during its life cycle. At select time intervals the samples are evaluated for various physical, chemical and performance characteristics to see how they have changed. If the changes are minimal to the company standards, the formula is “passed”. This means when the formula is shipped to the customers, it will be as good as when it was first produced. The underlying assumption in stability testing is that increasing storage temperature speeds up aging reactions that will occur. In the cosmetic industry, the “rule of thumb” is that a sample that is stored at 45° C. for 8 weeks is equivalent to one that is stored at room temperature for one year.
Thus there is a need for a color depositing shampoo made with cationic dyes, non-ionic and/or amphoteric surfactant(s), fragrance, and stabilizer that meets desired stability for such a product. There is also a need for a color depositing shampoo made with cationic dyes, non-ionic and/or amphoteric surfactant(s), fragrance, and stabilizer that is substantially free from anionic surfactants with good foaming properties to efficiently and effectively deliver the dyes to the hair.
It is thus an additional object of the present invention to provide a shampoo based formulation that will efficiently color the hair and effectively clean the hair which meets a certain minimum stability testing and meet a desired shelf life. It is also an object of the invention to provide a shampoo based formulation that will replace ordinary shampoo but also be useful as a hair dye, a composition with improved and more desirable foaming properties which also meets a certain minimum stability testing.